President Bush and Democratic presidential nominee John Kerry sparred over Iraq Monday as they campaigned in states where the race for the White House is extremely close. The presidential candidates appeared at picnics and rallies as Americans marked the Labor Day holiday.

Labor Day is the traditional start of U.S. presidential campaigns. But this year, the candidates are already working as if the election was just days away.

On this holiday that honors American workers, John Kerry's plan was to focus on jobs. But when he appeared at a campaign event near Pittsburgh, Pennsylvania, the audience brought up Iraq.

The candidate answered with blunt words, calling the president's talk of coalition troops fighting alongside U.S. forces a sham. "It is American troops that are ninety percent of the combat casualties, and it is American taxpayers that are paying ninety percent of the cost of this war. It is the wrong war, in the wrong place, at the wrong time.

Mr. Kerry said if elected, he would try to pull U.S. troops out of Iraq within four years. He said when he voted in the Senate to authorize the use of force, he warned the White House early on not to rush to war, to build a legitimate coalition, and to have a plan to keep the peace.

He said the president failed and the letter "W" in George W. Bush stands for wrong - wrong on everything from the war in Iraq to the U.S. economy. "We've added more debt to America in the last four years than we did from George Washington to Ronald Reagan. That is what is happening in this country," he said.

It was another sign that the Democratic presidential nominee is toughening up his rhetoric as polls show President Bush pulling ahead. In remarks to a Labor Day rally in Poplar Bluff, Missouri, Mr. Bush accused John Kerry of shifting positions on the war in Iraq once again.

"No matter how many times Senator Kerry changes his mind, it was right for America then, and it's right for America now that Saddam Hussein is no longer in power," he said.

Like Senator Kerry, Mr. Bush devoted most of his Labor Day remarks to the economy. He talked about taxes and job creation, saying his policies are making a positive difference at home and abroad.

"And I believe this nation wants steady, consistent and principled leadership and that is why, with your help, we are going to score a great national victory in November," he said.

The president will lead a caravan of campaign buses across Missouri on Tuesday. At the same time, Senator Kerry will be seeking votes in North Carolina and Ohio.